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Chemistry SM-1131 Week 2 Lesson 2. Dr. Jesse Reich Assistant Professor of Chemistry Massachusetts Maritime Academy Fall 2008. Class Today. Scavenger Hunt Review Quiz Answers Working with Density. The Hunt.
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Chemistry SM-1131Week 2 Lesson 2 Dr. Jesse Reich Assistant Professor of Chemistry Massachusetts Maritime Academy Fall 2008
Class Today • Scavenger Hunt Review • Quiz Answers • Working with Density
The Hunt • Ok, today we have to learn about density, but you’re going to learn about it on your own for a bit. You’re goal is the answer the following questions. When you are done ask for a quiz. When the quiz is done you are free to leave.
Hunt Objectives • What is the equation for density. • What is the density of water? • What is the density of mercury metal? Oak wood? Birch wood? Ethanol? Gasoline? Diesel? Air? • What happens when you put metal in water? Gasoline in water? Ethanol in water? • What does the term miscible mean? What does it have to do with the last question?
Also Join Wikispaces • Go to www.wikispaces.com • Click on get an account • Fill out the form, but don’t get a wiki of your own. • Check your email • Verify your account • Go to reich-chemistry.wikispaces.com and click join space. • Confirm with me that it all worked
Quiz 1 • Significant Figures, how many Sig Figs does each of the following numbers have? • 20,004,000 5 • 20,004,000. 8 • 000.00043 2 • 000.0004300 4 • 52,444 5
Quiz 2 • What is a hypothesis? How do experiments relate to hypothesizes? A theory. Something used to test theory. Good experiments only have 1 variable that are tested.
Quiz Q3 • Convert the following numbers into scientific notation • 20,004,000 2.0004e7 • 20,004,000. 2.004000e7 • 000.00043 4.3e-4 • 000.0004300 4.300e-4 • 52,000 5.2e4
Quiz Q4 • Round the following numbers to the third sig fig. • 20,004,000 20,000,000 • 157.9 158 • 000.00043222 0.000432 • 000.00043783 0.000438 • 52,270 52,300
Quiz Q5 • Add the following numbers, round, and put into scientific notation. • 5,002 + 3,000 + 1,575 = 1.0e4 • 150 + 25 + 88 = 2.6e2 • 12,000 + 15,000 + 200,000 2e5 • 43.332 - 59.2 - 9.004 -2.49e1 • 2.3e3 + 2.55e5+ 5.899e4 3.16e5
Quiz Q6 • Multiply the following numbers, round, and put into scientific notation • 43.30 * 15.2 / 12 = 5.5e1 • 20,202 / 2,000 * 1,525 = 2e4 • 241.005 * 15.2 / 150 2.4e1 • 0.0042 * 0.00123 * 0.0087 4.5e-7
Quiz Q 7-8 • Convert 1,500 inches into feet. (I don’t care about the number copy the form) 1,500 in * 1ft = 125ft 12 inches • Convert 162 ft into yards. (I want to see the form!) 162 ft * 1 yd = 54.0 yards 3 ft
Quiz Q 9 • Convert 2,220 inches into yards 2220 in * 1 ft * 1yd = 61.6666 => 12 in 3ft 61.7 => 6.17e1
Quiz Q10 • 50,000g into kg 50,000g * 1kg = 50kg 1000 g • 4,300 km into m 4,300 km * 1,000m = 4,300,000m 1 km
Quiz Q10 • 2.2 L into ml 2.2L x 1,000 mL = 2,200mL 1 L • 120 cm into inches 120 cm * 1 in = 47.2 2.54 cm
Quiz Q10 • Convert 2,500,542 seconds into years 2,500,542 sec * 1 min * 1 hr * 1 day * 1 year = 60 sec 60 min 24 hr 365 days = 0.079291666666 years = 0.07929167 years = 7.929167e-2
Density • Density = Mass volume d = m v
Let’s calculate density • I have a ball of metal that takes up 3ml and weighs 12.6g. What is it’s density? d = m v d= 12.6g= 4.2 g/ml, but 3ml only has 1 sig fig 3ml OK so, finally 4 g/ml would be the answer!
Let’s use density • In lab I draw out 15ml of a liquid that has 1.67 g/ml. How much mass does it have? • (copy the given, and use the density) 15ml * 1.67 g = 25.05g ml
Let’s use density… Again • A recipe calls for 200.ml of ethanol, which has a density of 0.789g/ml. How many grams did we add? 200. ml ethanol* 0.789 g ethanol= 157.8 ethanol ml 158g => 1.58g e2
Time Left • OK, we’re going to work on Wikis This only works if you have signed in • 1 open up the web page • 2 click on the atomic history wiki-timeline link • 3 click on your class • 4 click edit this page • Type in: Fall.2008.MMA.lastname1.lastname2.timeline
Making a link • Highlight the text you just wrote • Click on the icon in the top bar that has a chain in it. • Click ok when the pop up comes • Click Save • If you do something bad like erase someone else’s don’t save what you did. Just hit cancel.
Once you make a link • Click on your link • Hit edit this page • Type in John Dalton looks like D. Reich • Hit Save • Notice how all the computers in the world can now see that John Dalton looks like D. Reich • You’re going to make your wiki like this. • Be sure to save often!